raft: Fix raft_is_connected() when there is no leader yet.

If there is never a leader known by the current server, it's status
should be "disconnected" to the cluster. Without this patch, when
a server in cluster is restarted, before it successfully connecting
back to the cluster it will appear as connected, which is wrong.

Signed-off-by: Han Zhou <hzhou@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/ovsdb/raft.c b/ovsdb/raft.c
index 4789bc4f2..6cd7b0041 100644
--- a/ovsdb/raft.c
+++ b/ovsdb/raft.c
@@ -298,6 +298,11 @@ struct raft {
     bool had_leader;            /* There has been leader elected since last
                                    election initiated. This is to help setting
                                    candidate_retrying. */
+
+    /* For all. */
+    bool ever_had_leader;       /* There has been leader elected since the raft
+                                   is initialized, meaning it is ever
+                                   connected. */
 };
 
 /* All Raft structures. */
@@ -1024,7 +1029,8 @@ raft_is_connected(const struct raft *raft)
             && !raft->joining
             && !raft->leaving
             && !raft->left
-            && !raft->failed);
+            && !raft->failed
+            && raft->ever_had_leader);
     VLOG_DBG("raft_is_connected: %s\n", ret? "true": "false");
     return ret;
 }
@@ -2519,7 +2525,7 @@ static void
 raft_set_leader(struct raft *raft, const struct uuid *sid)
 {
     raft->leader_sid = *sid;
-    raft->had_leader = true;
+    raft->ever_had_leader = raft->had_leader = true;
     raft->candidate_retrying = false;
 }